The interaction of tribenzocyclyne (TBC) with metal moieties has resulted in the synthesis of a wide variety of novel metallic derivatives. During our studies of the reaction chemistry of small molecules with nickel(s) cyclotriyne complexes, we have observed significant reactivity differences that appear to be primarily correlated to the size of the central pocket. We are currently synthesizing TBC analogs in which one of the phenyl rings is replaced with another moiety such as an ER2 unit (E = S:, Ge, Ti . . .). Such a replacement will change the size and the electronics of the cyclotriyne. FAB-MS has been used to characterize these complexes.